For an electronic element, electromagnetic interference (EMI) usually occurs and affects neighboring electronic circuits via electromagnetic induction, electrostatic coupling, or conduction. Disturbance due to electromagnetic interface may degrade performance or cause malfunction of the electronic circuits. Therefore, electromagnetic shielding such as blocking interference of high frequency electromagnetic signals should be considered while designing electronic modules. Furthermore, the progressive miniaturization of electronic modules in recent years will worsen the disturbance, and it is difficult or expensive to build electromagnetic shielding structures within tiny space between electronic circuits.
Electromagnetic shielding solutions include board-level shielding and package-level shielding. The package-level shielding can be applied to smaller electronic module. For example, conformal shielding and compartment shielding are developed to achieve electromagnetic shielding in small space. A simplified, flexible, easily controllable and cost-effective method for forming an electromagnetic shielding structure in a miniaturized electronic module with high yield rate is desired.